Facial feature evaluation based on eye location

ABSTRACT

One embodiment of the present invention includes interrogating a location along a face of a person with multiple wavelengths of electromagnetic radiation. Signals are established corresponding to detection of the wavelengths reflected from the location. A determination is made as to whether a disguising material covers at least a part of the face based on a difference in range to the location indicated by these signals. Alternatively, the signals may correspond to reflections by different portions of an eye of the person and a determination is made regarding the location of one or more eyes of the person based on the signals. In one particular nonlimiting form, a multispectral, three-dimensional signature of facial features is registered to eye location that may include the iris, nose, chin, mouth, check or the like for facial recognition/identification.

BACKGROUND

The present invention relates to facial feature evaluation, and moreparticularly, but not exclusively is directed to multispectral facialinterrogation techniques for locating the eyes and/or related facialfeatures.

Viable facial recognition techniques continue to be of interest in manyapplications; including but not limited to, security screening,transaction authorization, access control, and the like. Unfortunately,many existing systems suffer from high rates of misidentification,excessive complexity, large conspicuous device size, and/or slowprocessing times. Accordingly, there is an ongoing demand for furthercontributions in this area of technology.

SUMMARY

One embodiment of the present invention is a unique facial featurerecognition technique. Other embodiments include unique systems,devices, methods, and apparatus to interrogate, recognize, and/or locatefacial features. Further embodiments, forms, features, advantages,aspects, and benefits of the present invention shall become apparentfrom the detailed description and figures provided herewith.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a partial, diagrammatic view of a facial evaluation system.

FIG. 2 is a diagrammatic view of a laser subsystem of the system of FIG.1.

FIG. 3 is a diagrammatic view of one form of laser arrangement that maybe included in the subsystem of FIG. 2.

FIG. 4 is a signal diagram relating to eye location determined with thesystem of FIG. 1.

FIG. 5 is a diagrammatic view of a millimeter wave subsystem of thesystem of FIG. 1.

FIG. 6 illustrates a matrix of parameters that can be utilized inperforming facial evaluation/recognition with the system of FIG. 1.

FIG. 7 is a flowchart of one mode of operating the system of FIG. 1.

FIG. 8 is a system for evaluating an iris of the eye that includes thelaser subsystem of FIGS. 2 and 3.

FIG. 9 is a flowchart of one mode of operating the system of FIG. 8.

FIG. 10 provides computer-generated images of an eye to further explainselected aspects of the system of FIG. 8.

DETAILED DESCRIPTION

While the present invention may be embodied in many different forms, forthe purpose of promoting an understanding of the principles of theinvention, reference will now be made to the embodiments illustrated inthe drawings and specific language will be used to describe the same. Itwill nevertheless be understood that no limitation of the scope of theinvention is thereby intended. Any alterations and further modificationsin the described embodiments, and any further applications of theprinciples of the invention as described herein are contemplated aswould normally occur to one skilled in the art to which the inventionrelates.

FIG. 1 depicts facial evaluation system 20 of one embodiment of thepresent invention. System 20 is configured to scan face F to evaluateselected features. In one form, this evaluation is performed for afacial recognition application. System 20 includes facial scanningequipment 40 operatively coupled to processing subsystem 24. Alsocoupled to processing subsystem 24 are one or more operator input (I/P)devices 26, one or more operator output (O/P) devices 28, and computernetwork 30. Processing subsystem 24 includes pre-processor 32 and dataprocessor 34. Also included in processing subsystem 24 is memory 36.Memory 36 includes Removable Memory Device (RMD) 38. Facial scanningequipment 40 includes color imager 42, millimeter wave subsystem 50, andlaser subsystem 70.

Operator input devices 26 can include a keyboard, mouse, or otherpointing device; a voice recognition input arrangement; and/or adifferent arrangement as would occur to those skilled in the art.Operator output devices 28 can include a display, a printer, a speakersystem, and/or a different arrangement as would occur to those skilledin the art. Computer network 30 can be provided in the form of a LocalArea Network (LAN), a Municipal Area Network (MAN), and/or a Wide AreaNetwork (WAN) of either a private type, a publicly accessible type, suchas the internet; or a combination of these.

Pre-processor 32 and processor 34 can each be comprised of one or morecomponents configured as a single unit, or as a number of separateunits. When of multicomponent form, either may have one or morecomponents remotely located relative to the others, or otherwise haveits components distributed throughout system 20. Pre-processor 32 andprocessor 34 can each be of a general purpose integrated circuit type, asemicustom type, a fully customized type, or such different type aswould occur to those skilled in the art. In one form, pre-processor 32is based on a Field Programmable Gate Array (FPGA) that is configuredwith operating logic to directly process input signals from equipment 40and provide corresponding output-signals. In one particular FPGAembodiment of pre-processor 32, the input signals are provided to theFPGA at an output frequency and the output signals are provided asmultiple frames of data with an output frequency less than the inputfrequency. This data is typically useful to recognize scanned face F,providing a form of “signature” information specific an individual'sface. By way of nonlimiting example, the ratio of input frequency tooutput frequency for this embodiment is about ten to one (10:1).Additionally or alternatively, processor 34 can be of general purposetype that is programmed with software instructions to process digitaldata received from pre-processor 32. Processor 34 can be provided withonly a single Central Processing Unit (CPU); or alternatively multipleCPUs arranged to operate independent of one another, and/or in aparallel, pipelined, or different processing arrangement as would occurto one skilled in the art. One or more components of pre-processor 32and/or processor 34 may be of an electronic variety defining digitalcircuitry, analog circuitry, or a combination of both. As an addition oralternative to electronic circuitry, pre-processor 32 and/or processor34 may include one or more other types of components or controlelements. Either or both of pre-processor 32 and processor 34 may beprogrammable, a state logic machine or other operationally dedicatedhardware, or a hybrid combination thereof.

In one embodiment including electronic circuitry, processor 34 includesone or more integrated digital processing units operatively coupled toone or more solid-state memory devices defining, at least in part,memory 36. For this embodiment, memory 36 provides storage forprogramming instructions executable by the one or more processing unitsand/or can be arranged for reading/writing of data in accordance withone or more program routines.

It should be appreciated that pre-processor 32 and processor 34 eachoperate in accordance with logic arranged to perform various routines,operations, conditionals, and the like—including those described inconnection hereinafter. This operating logic can be in the form ofsoftware programming instructions, firmware, a programmable gate, array,application specific circuitry, and/or other hard-wired logic/circuitry,just to name a few examples. Furthermore, such logic can be in the formof one or more signals carried with/encoded on memory 36, or morespecifically RMD 38 of memory 36, and/or one or more parts of computernetwork 30. In one example, logic signals to perform one or moreoperations (such as programming) are transmitted to/from pre-processor32 and/or processor 34 via network 30. Alternatively or additionally,programming can be transported or disseminated through RMD 38 or one ormore other portable storage devices.

Memory 36 may include one or more types of solid-state semiconductorelectronic devices and additionally or alternatively may include amagnetic or optical memory variety. For example, memory 36 may includesolid-state electronic Random Access Memory (RAM), SequentiallyAccessible Memory (SAM), Programmable Read Only Memory (PROM),Electrically Programmable Read Only Memory (EPROM), ElectricallyErasable Programmable Read Only Memory (EEPROM), or flash memory; anoptical disk memory (such as a CD or DVD); a magnetically encoded harddisk, floppy disk, tape, or cartridge media; or a combination of any ofthese types. Further, memory 36 may be volatile, nonvolatile, or ahybrid combination of these. RMD 38 may be of an optically encodeddevice (such as a disk) or magnetically encoded disk, tape, or cartridgetype; a semiconductor-based card or “stick”; and/or such different formof portable/removable memory as would occur to those skilled in the art.

Besides the depicted devices, processing subsystem 24 may also includeany control clocks, power supplies, interfaces, signal conditioners,filters, limiters, Analog-to-Digital Converters (ADCs),Digital-to-Analog Converters (DACs), wireless communicationports/interfaces, wire, fiber, or cable-connected communicationports/interfaces, or other types of circuits, devices, operators,elements, or components as would occur to those skilled in the art toimplement the present invention.

Referring to FIG. 2, further details are depicted regarding oneembodiment of laser subsystem 70. Laser subsystem 70 includesmultispectral source 72, detector 82, and Radio Frequency (RF) signalprocessing circuitry 92. Source 72 includes lasers 74 a and 74 b(alternatively designated laser A and laser B). Detector 82 includessensors 84 a and 84 b (alternatively designated sensor A and sensor B).RF signal processing circuitry 92 is operatively coupled to source 72.Circuitry 92 controls certain operations of source 72 by providingcorresponding control signals. Detector 82 is also operatively coupledto RF signal processing circuitry 92. Detector 82 provides correspondingsensor signals to circuitry 92 for processing in relation to the controlsignals sent to source 72. For example, circuitry 92 includes modulationcircuitry 94 to provide modulating signals to source 72. Circuitry 92also includes RF signal information recovery circuitry 96. Circuitry 96processes signals received from detector 82 to recover interrogationinformation and put it in a form more suitable for subsequent processingby subsystem 24. Circuitry 96 includes filter circuitry 98 a to reduceor remove one or more undesired frequencies/harmonics, andAnalog-to-Digital (A/D) Converter (ADC) 98 b to convert recoveredinterrogation information to a digital format. Corresponding digitaloutput signals are provided from ADC 98 b to processing subsystem 24. Itshould be appreciated that in other embodiments subsystem 24 canalternatively or additionally be configured to include at least some ofcircuitry 92, such as filter circuitry 98 a, ADC 98 b, and the like.

FIG. 3 illustrates further details of one form of subsystem 70. In FIG.3, only laser 74 a of source 72, sensor 84 a of detector 88, and channelsubcircuitry 90 of circuitry 92 are illustrated to preserve clarity—itbeing understood that laser 74 b and sensor 84 b are configured in alike manner, with corresponding subcircuitry belonging to circuitry 92(not shown). Laser 74 a includes laser diode 76 connected to controlcircuitry 78. Sensor 84 a is connected to amplifier 88, which in oneform could be utilized to dynamically adjust amplification in anAutomatic Gain Control (AGC) arrangement. Also shown in FIG. 3, RFprocessing circuitry 92 further includes oscillator 94 a and modulationsource 95 that are combined with mixer 94 c. Mixer 94 c provides asinusoidal modulation signal to control circuitry 78 of laser 74 a.Phase shifter 94 b, which is also included in subcircuitry 90, providesa 90 degree phase-shifted form of the signal from oscillator 94 a.Oscillator 94 a, phase shifter 94 b, mixer 94 c, and source 95 arecollectively included in modulation circuitry 94 of FIG. 2, but are notshown specifically therein to preserve clarity.

Channel subcircuitry 90 also includes frequency mixer 96, which is partof RF signal information recovery circuitry 94. Circuitry 96 includesmixers 96 a and 96 b to output corresponding in-phase (I) and quadrature(Q) signals of a standard type. Also included in circuitry 94 isconverter 97. Converter 97 converts I and Q inputs from mixer circuitry96 to provide corresponding amplitude and gain outputs. This amplitudeand gain information is provided as “channel A” corresponding to laser74 a and sensor 84 a. The amplitude and phase signals of channel A arefiltered by circuitry 98 a, converted to a digital form by A/D converter98 b, and provided to processing subsystem 24, as shown in FIG. 2. Itshould be understood that circuitry 92 includes circuitry likesubcircuitry 90 to interface with laser 74 b and sensor 84 b, andprovide corresponding “Channel B” amplitude and phase outputs.

In one form, circuitry 78 of laser A and B includes a laser currentdriver and a bias-T for inserting Amplitude Modulation (AM). Alsoincluded are standard collimation optics, connectors, and the like. Forthis form, detector 82 includes collection optics, a high-speedphotodetector form of sensor A and B, a pre-amplifier, an automatic gaincorrection (AGC) amplifier, and frequency mixers 96 a and 96 b in theform of an integrated RF circuit component provided by ANALOG DEVICES asmodel number AD8302. Pre-processor 32 provides range image data byprocessing both the intensity and phase shift of the reflected beam(with respect to the transmitted beams of different wavelengths). Thequadrature phase channel B provides a signal that can be used toaccommodate target T positioning at the 2π radians range ambiguityinterval. Naturally, in other embodiments, differentcircuitry/components can additionally or alternatively be utilized. Amore detailed description of subsystem 70 and corresponding signalinformation processing follows.

Referring generally to FIGS. 2 and 3, subsystem 70 determines range totarget T (such as an individual) in accordance with an observed phasechange of modulated electromagnetic radiation of a given wavelength (orwavelength range) that is observed by comparing a modulated incidentbeam IB emanating from source 72 to the beam reflected by target T inresponse (as sensed with detector 82). This reflected beam issymbolically designated by the reference label RB and the reflectingsurface is symbolically designated by the reference label RS.

The phase comparison laser measurement technique of subsystem 70utilizes amplitude modulated (AM) continuous wave (CW) laser diodetransmitters (lasers 74 a & 74 b). In this AM/CW laser scheme, the laserbeam amplitude is modulated between zero and a maximum intensity at aspecific frequency provided by oscillator 94 a. Both intensity and phaseshifting of the reflected beam RB (with respect to the incident beam IBfrom source 72) are simultaneously detected with detector 82. Comparingthe transmitted and received signal phase provides a high resolutiontarget range measurement. The resolution D of this measurement isdetermined by the phase angle between the transmitted modulated waveform(IB) and the received modulated waveform (RB). The relationship betweenphase angle Δφ_(r) (radians), time delay t_(r), speed of light c, andmodulation frequency f_(o), is given by the following equations (1) and(2):t _(r)=Δφ_(r)/2πf _(o)  (1)D=ct _(r)/2=cΔφ _(r)/4πf _(o)  (2)Selecting a desired distance resolution of 2.0 mm and a phase resolutionof Δφ_(r)=5°, the desired AM modulation frequency is given byrearranging equation (2) to the equation (3) form that follows:f _(o) =cΔφ _(r)/4πD  (3)

Based on equation (3), the corresponding working frequency becomesapproximately f_(o)=1.0 GHz. This modulation rate sets an ambiguityinterval of the phase-loaded measurement that results for phase turns of360° or more (2π radians). The total range corresponding to a completephase turn (0-360°) at this frequency is 0.300 m (D_(range)=c/(2f_(o))). This ambiguity interval provides sufficient depth to fullyimage face F at target T (see FIG. 1). To address applications wheresuch ambiguity cannot otherwise be accommodated, the AM/CW transmitteris switched to a Time-Of-Flight (TOF) measurement to measure theabsolute distance to target T. This TOF information can be used to scalethe laser range data, and any resulting images, to other detected/sensedinformation to be described hereinafter.

Stated differently, the phase-based measurement provides a degree of“fine” resolution, while the TOF measurement provides a degree of“coarse” resolution. This coarse TOF measurement effectively delimitsthe range that is refined with the phase-based measurement. In oneparticular form, TOF measurement can be made with a burst of coherentencoded energy from the laser as described in U.S. Pat. No. 5,745,437;however, in other embodiments different approaches for the “coarse”measurement can be alternatively or additionally used. It has been foundthat for certain applications the phase-based comparison approachprovides acceptable performance in terms of cost and complexity forranges of 30 meters or less—particularly in the area of facialrecognition as will be further explained hereinafter. Naturally, inother embodiments different techniques may be alternatively oradditionally employed, such as Time-Of-Flight (TOF), triangulation,and/or interferometry, to name a few.

To evaluate various facial features, determining eye location is oftenof interest. Facial scanning equipment 40 is arranged to locate one ormore eyes based on the wavelength-selective retroreflection of lightfrom the retina R of the human eye. Called “cat's eye” reflection, thisphenomenon produces the red-eye effect sometimes seen in photographs.Accordingly, eye E is alternatively designated retroreflector 22. Byselecting different wavelengths for laser A and laser B, differentranges for retina R and a part of the eye closer to source 72 (such asthe outer surface OS of eyeball E in FIG. 2) can be observed. Acorresponding range difference relatively unique to eye E for theselected wavelengths can be used to determine where an eyeball islocated relative to a timed scan of a typical human face. FIG. 2 furtherillustrates the approach, symbolically showing that thewavelength-selective light from laser 74 a is reflected by retina R ofeyeball E, while wavelength-selective light from laser 74 b is reflectedby outer surface OS of eyeball E. Sensor 84 a is arranged to selectivelydetect the laser 74 a wavelength reflected by retina R, and sensor 84 bis arranged to selectively detect the laser 74 b wavelength reflected byouter surface OS. Pupil P and Iris I of eyeball E are also illustratedis FIG. 2 for reference. It should be appreciated that the radiationfrom laser 74 a passes through pupil P as it is transmitted to andreturned from retina R.

For this approach, laser wavelength selection bears on the contrastbetween retina R and outer surface OS reflection desired for eyedetection. In one embodiment, 0.9 and 1.55-micron laser wavelengths areutilized for lasers 74 a and 74 b, respectively. Transmission from theretina R is approximately 87% at 0.9 microns and 0% at 1.55 microns. Thereflectivity of the eyeball outer surface OS is about 2% at 1.55microns. Assuming all the light is returned to detector 82, theamplitude ratio is about 0.87/0.02=43.5. Further, the reflectivity ofhuman skin at 0.9 and 1.55 microns wavelength is in the range of 84% and27% respectively. Assuming all the light is returned to detector 82, theamplitude ratio is 0.84/0.27=3.1. Therefore the eyeball detectioncontrast is enhanced by over a factor of ten using this dual wavelengthapproach. Further discrimination is provided as a result of therelatively longer round-trip travel of the 0.9-micron wavelength beam(IB and RB) through the interior of eyeball E. The path difference(z₁−z₂) between the dual laser radar wavelengths differs by a measurableamount. A typical human eyeball E has a diameter of about 25 millimeter(mm). Accordingly, a 2 mm range resolution provides about a 25-to-1z₁−z₂ signal differentiation.

For the wavelength selections of 0.9 micron (laser 74 a) and 1.55microns (laser 74 b) it should be appreciated that the two correspondinglaser beams are invisible to humans. Consequently, utilization of thesewavelengths is more covert than visible light. Furthermore, it has beenfound that these wavelengths transmit through optical glass and opticalplastic at a relatively high level (about 90% and 85% respectively),which are materials commonly used to make lenses of eyeglasses.Nonetheless, in alternative embodiments, one or more of thesewavelengths may be different as would occur to those skilled in the art.

More specifically describing information recovery with circuitry 92,evaluation of the amplitude and phase shift of the received sinusoidalsignal, represented as “S” with respect to the AM modulation sinusoidalsignal, represented as “R,” provides the target range information, asexpressed in the following equations (4) and (5):R=A _(R) sin(ωt+φ _(R))  (4)S=A _(S) sin(ωt+φIB _(S))  (5)A_(S) will have a constant amplitude and A_(R) and φ_(R) can beevaluated using the complex form for the sinusoidal oscillation, asgiven by equation (6) that follows:e ^(jω) ¹ ^(t)=cos(ω₁ t)+j sin(ω₁ t)  (6)by multiplying equations (4) and (5) by equation (6), and eliminatingthe components at frequency ω+ω₁, the quadrature down conversion ofsignals R and S is obtained at a frequency ω_(d)=ω+ω₁, thus obtainingequations (7) and (8) as follows:

$\begin{matrix}{S_{d} = {{- j}\frac{A_{S}}{2}{\mathbb{e}}^{j{({{\omega_{d}t} + \phi_{S}})}}}} & (7) \\{R_{d} = {{- j}\frac{A_{S}}{2}{\mathbb{e}}^{j{({{\omega_{d}t} + \phi_{R}})}}}} & (8)\end{matrix}$By multiplying equation (7) by the complex conjugate of equation (8),equation (9) is obtained as follows:

$\begin{matrix}{Y = {A_{S}\frac{A_{R}}{4}{\mathbb{e}}^{j{({\phi_{S} - \phi_{R}})}}}} & (9)\end{matrix}$Equation (9) represents a vector whose unit of measurement isproportional to A_(S) and whose phase is equal to φ_(S)−φ_(R).

FIG. 4 shows a signal diagram resulting from one experimental example ofthe present application with an experimental equipment set-upcorresponding to subsystem 70. This diagram is based on 0.9 and1.55-micron (μm) wavelength selections for lasers 74 a and 74 b,respectively. In FIG. 4, line scan 99 a and line scan 99 b show relativedetected intensity information returned at the respective 0.9 micron(μm) and 1.55 (μm) wavelengths. The ratio of intensity (magnitude) ofA₁/A₂ is illustrated in line scan 99 c, and the difference in rangez₁−z₂ as determined by phase change is shown in line scan 99 d. Theposition of the eye (eyeball) relative to the scan timing is alsodesignated by reference numeral 100. As a result, not only phasedifference, but also magnitude difference can be used to discriminateeye location. The location of one or more eyes relative to the otherfacial range information can be determined from the scan timing. Besideeye location, range information, and corresponding imagery; other facialinterrogation techniques are provided by system 20.

Next, referring to FIGS. 1 and 5, millimeter wave subsystem 50 isfurther described. Subsystem 50 is included in equipment 40 to enhancebiometric information corresponding to Target T, as will be furtherdescribed hereinafter. Subsystem 50 is arranged with interferometer 51that includes Voltage Control Oscillator (VCO) 52 connected to mixer 54and antenna 56 by couplers 57 a and 57 b as shown in FIG. 5. Mixer 54 isoperatively connected to analog signal processing circuitry 58.Oscillator 52 outputs a signal to couplers 57 a and 57 b, and to mixer54. Coupler 57 b further includes an amplifier to drive antenna 56 withthe oscillator output signal. It should be appreciated that in otherembodiments oscillator 52 may be of a fixed frequency type rather than aVCO and/or be in the form of a different time varying source to providea drive signal at the desired frequency.

Circuitry 58 includes components to provide an Intermediate Frequency(IF) derived from oscillator 52 and mixer 54 to provide rangeinformation relating to the distance of Target T from antenna 56 in astandard manner. Circuitry 58 provides an analog signal corresponding tothis range information. Circuitry 58 is connected to filter 60 forfiltering-out undesirable frequencies (i.e., harmonics) from theinformation signal. This filtered signal is then provided toAnalog-to-Digital Converter (ADC) 62 for conversion to a digital format.In one form, the filtered signal input to ADC 62 is oversampled at fourtime (4×) the Nyquist criterion sampling rate to generate I and Qdemodulated outputs in accordance with standard techniques. ADC 62 iscoupled to detector 63 to detect the desired information. For a 4×sampling rate with ADC 62 to provide I and Q outputs, detector 63 couldbe defined within subsystem 24. In other arrangements, differentinterrogation, sampling, modulation/demodulation, or the like can beused as would occur to one skilled in the art.

In the depicted embodiment, interferometer 51 uses a monostatic antennaarrangement that transmits and receives millimeter waves. Antenna 56 isconfigured for a narrow beam pattern (spot size) that is mechanicallyscanned to measure facial dimensions. For some applications, it ispreferred that high millimeter-wave frequencies (200-400 GHz) beutilized to provide a relatively small subsystem size.

Subsystem 50 utilizes low-power millimeter waves (radar signals) toilluminate the person being measured. These interrogation signals canpenetrate typical clothing material, but are reflected/scattered by skinof the human body. Reflected signals are detected and processed withsystem 20 to capture spatial coordinate data. From this data,three-dimensional (3-D) measurement and corresponding representations(images) of human facial features can be provided to complement thethree-dimensional range data gathered with subsystem 70. Furthermore,millimeter wave signals can readily penetrate optically opaque materialssuch as body hair, make-up, and disguises. Correspondingly, typicalclothing, make-up, disguise materials, and hair are generallytransparent to the millimeter wave interrogation signals.

As illustrated in FIG. 5, a schematic partial cross section of target Tis shown, including a layer of skin 64 with boundary 64 a, and disguiselayer 66 with boundary 66 a, which covers boundary 64 a of skin 64.Boundary 66 a is generally coextensive with outer surface OS for theFIG. 5 cross section. Subsystem 50 penetrates disguise layer 66,reflecting from skin 64 at boundary 64 a. While subsystem 50 providesinformation representative of facial skin topology—including boundary 64a covered by disguise layer 66, 3-D data gathered with subsystem 70typically is reflected by make-up and disguise materials, such asboundary 66 a of disguise layer 66. By comparing data obtained withsubsystem 50 and subsystem 70, make-up or other disguise or skincovering materials can be discovered that might otherwise go undetected.

From subsystem 50 and/or subsystem 70, 3-D facial biometrics can becomprised of dimensional information from the scanned individual'sanatomy. Once an individual reaches maturity (adulthood), his or herskeletal anatomy does not normally change dramatically over time(exceptions can include accident or disease). Corresponding surface dataenables calculation of critical 1D, 2D and 3D skeletal dimensions andanthropometric measurements. The length and shape of various bones canbe obtained from surface evidence (e.g., joints, skin protrusions).Because the skin covering the cranium is fairly thin, volumetricmeasurements of the skull and critical anthropometric data (e.g.,placement, shape and distance between eye sockets) can also be obtainedfor those applications where desired.

In FIG. 1, facial scanning equipment 40 further includes color imager42. Color imager 42 provides imagery of target T in the standard colorvideo Red-Green-Blue (RGB) format for processing subsystem 24. Thiscolor image data can be used to compliment data gathered with subsystems50 and 70. For example, color images of a target T can be used toprovide a visual representation of target T to an operator—with orwithout an indication of other information determined with subsystem 50and/or subsystem 70.

3-D facial scanning equipment 40 provides a rich feature vector space,where multispectral and/or multilayer 3-D range imagery are combined toprovide information regarding target T. Feature vector space can becharacterized with the analog video RGB channels, the signal amplitudesA, z ranges, and/or TOF measurements from subsystem 70, and millimeterwave information from subsystem 50 including path length and amplitudedifferences. FIG. 6 symbolically presents a matrix of parameters thatcan be used to provide unique biometric characterizations of face F oftarget T. In FIG. 6, color/image information from imager 42 isrepresented by the RGB color components (1st column). Amplitude/rangefor laser A and laser B are represented by A₁/z₁ and A₂/z₂,respectively. An amplitude comparison corresponding to a difference orratio is represented by ΔA (proportional to A₁/A₂ and/or A₁-A₂) and arange comparison corresponding to a difference in ratio is representedby ΔZ (proportional to Z₁/Z₂ and/or Z₁−Z₂). Amplitude and rangeindicated by millimeter wave interrogation are represented by A_(mmw)and Z_(mmw), respectively. TOF is also represented in the matrix of FIG.6. The feature vectors are digitized at an analog color basebandfrequency. Circuitry 25 can correspondingly provide a “color video” datafusion output in a multispectral format. For this approach, the laserbeams from both lasers of subsystem 70 and the millimeter waves ofsubsystem 50 are raster-scanned across the target T at scanning ratescompatible with data fusion and analog video. In one form, some or allof the FIG. 6 parameters are generated by pre-processor 32 as a set ofsignals that define a facial ‘signature’ in multiple frames. Thesesignature signals provide data from which scanned face F can berecognized/identified.

Referring generally to FIGS. 1-5 and specifically to FIG. 7, procedure120 of another embodiment of the present application is illustrated inflowchart form. Procedure 120 is implemented with system 20, andappropriately configured operating logic of subsystem 24 and equipment40. This operating logic can be in the form of programming instructions,hardwired sequential or combinational logic, and/or adaptive or fuzzylogic, to name just a few possibilities.

Procedure 120 begins with operation 122 in which equipment 40 isutilized to scan face F of target T. Scanning of operation 122 includesgenerating at least two different selected wavelengths A and B ofsubsystem 70 to provide a topological scan of face F and locate eyes E1and E2 thereof. Also included is a scan with subsystem 50 to penetratedisguises, make-up, hair, and the like, while being reflected by skin oftarget T to provide corresponding 3-D facial data. In addition, colorimage information is provided with subsystem 42 during operation 122.Collectively, this signature data can be provided and grouped intoframes with pre-processor 32, and input to processor 34, which performssubsequent operations/conditionals.

From operation 122, procedure 120 continues with parallel operations 124a and 124 b. In operation 124 a, eye location is determined as describedin connection with subsystem 70. In operation 124 b, disguise or make-uppresence is determined by comparing data obtained with subsystems 50 and70. Notably, while operations 124 a and 124 b are performed in parallel,in other embodiments they can be performed in sequence in any order.

From operations 124 a and 124 b, procedure 120 continues with operation126. In operation 126, desired three-dimensional facial featureinformation is developed to provide a basis to uniquely identify targetT for facial recognition purposes or the like. Examples of the type ofinformation that could be developed in operation 126 arecharacterizations of the type described in connection with FIG. 6.Alternatively or additionally, this information could be based oneye-to-eye vector distance V and various vectors determined in relationto eye location or vector V including, for example, vectors to cheeksCK1 and/or CK2, mouth-corners M1 and/or M2, nose N1, and/or chin C1,(see FIG. 1)—to name just a few possibilities.

From operation 126, operation 128 of procedure 120 is performed. Inoperation 128, at least a portion of the information developed inoperation 126 is compared to identification data stored on a localand/or remote identification database. This database can take any ofseveral forms. In one example, a two-dimensional image database isutilized from which 3-D constructs are created. 3-D informationdetermined in operation 126 is then compared in operation 128.Additionally or alternatively, 3-D information obtained in operation 126can be converted to two-dimensional data for comparison to atwo-dimensional database of identification information. In oneparticular example, the three-dimensional data from system 20 isconverted to five two-dimensional images for comparison to images in apreexisting two-dimensional image database. In still another example, anew three-dimensional database can be developed for use in thecomparison of 128. In yet other examples, these approaches are combined.

Procedure 120 continues from operation 128 with conditional 130. Inconditional 130, it is tested whether the comparison of 128 indicates asuitable match of target T to information present in the correspondingdatabase. If the test of conditional 130 is true (affirmative), thenprocedure 120 continues with operation 132 in which an alert is providedto an operator. Such operator can be locally or remotely positioned withrespect to equipment 40 and/or target T. If the test of conditional 130is false (negative) then procedure 120 continues with conditional 134.Conditional 134 tests whether to continue scanning target T or anothertarget. If the test of conditional 134 is true (affirmative) procedure120 loops back, returning to operation 122 to perform the 122-128sequence again for submission to conditional 130. This loop can berepeated as desired based on the outcome of conditional 134. If the testof conditional 134 is false (negative), then procedure 120 halts.

Procedure 120 is but one example of a mode of operating system 20. Itshould be appreciated that many combinations, rearrangements, deletions,and the like are contemplated in other embodiments. For example, inother embodiments one or more of subsystems 42, 50, or 70 may be absent.In still other embodiments, the selected wavelengths of electromagneticradiation utilized for interrogation by subsystem 70 may vary as deemedappropriate. Likewise, the nature and type of interrogation performedwith millimeter waves can vary with adaptations made to subsystem 50 asappropriate. Further, subsystem 42 can be altered as appropriate. In oneparticular example an infrared scan with corresponding colorrepresentation is provided as an addition or alternative to subsystem42. In still other embodiments, one or more subsystems or aspects ofsystem 20 are applied to one or more other portions of a person's bodyas an addition or alternative to face F. Further, system 20 orsubsystems thereof may be utilized in connection with the interrogationof objects other than a person. In one particular embodiment, subsystem70 is utilized to determine eye location for a different facialevaluation technique that may be provided with or without subsystem 50and/or 42. Processing subsystem 24 would be adapted for any of thesevariations as appropriate to the particular operating goals of thealternative embodiment. In yet further embodiments, multispectralinterrogation is used to detect and/or evaluate inanimate objectsincluding one or more retroreflectors. In one particular example,retroreflectors in optical tags can be interrogated in such embodiments.Furthermore, retroreflectors can be used for device labeling, as amarker, to encode data, and the like—all of which can beinterrogated/determined in accordance with the present invention.

In one example of an alternative embodiment, FIG. 8 illustrates system220 for evaluating an iris of the eye obtained from scanning a “sea offaces” as illustrated by the example designated by reference numeral222. In the embodiment of FIG. 8, like reference numerals refer to likefeatures. System 220 includes laser subsystem 70 as previouslydescribed. System 220 further includes optical scanning and detectionsubsystem 324, detector processing circuitry 226, and data processingsubsystem 228. Also represented is a scan synchronized image scene assymbolically portrayed in FIG. 8.

Subsystem 224 includes a multifaceted scanning mirror 230 coupled todrive/control 232. Drive/control 232 controllably spins mirror 230 toprovide a Field Of View (FOV) capable of scanning several faces from adesired separation distance. In one example, a 30° FOV is scanned, whichhas been found to allow up to 12 faces to be examined in one scan at 8meters. The resulting scan is reflected on front surface mirror 234,which is driven by galvometer drive/control 236. The resulting beam 237is directed to beam splitter 238 to provide a beam input 237 a tosubsystem 70 and beam input 237 b to optics arrangement 240. Opticsarrangement 240 includes cylindrical lens 242, refractive prism 244, andmultispectral detectors 246. Cylindrical lens 242 compresses verticalscan pixels into a linear array that is spread with prism 244 acrossdetectors 246. In one form, three detectors 246 are providedcorresponding to three different laser wavelengths used for thescan—particularly 980 nanometers, 1200 nanometers, and 1550 nanometers.Referring to the subsystem 70 description, it should be appreciated that980 nanometers is approximately 0.9 microns and 1550 nanometers isapproximately 1.55 microns. Signals from detectors 246 are input todetector processing circuitry 226 for recovery, conditioning, andconversion to a desired digital format. These digital signals are thenoutput by circuitry 226 to processing subsystem 228.

Processing subsystem 228 performs in accordance with operating logic asdescribed in connection with system 20. Included in this logic, is theprocessing of signals from subsystem 70 to detect eye location and toperform analysis of an iris of the eye in accordance with standard irisdetection algorithms. In one particular form, a 512 byte iris code usingwavelet compression is derived from iris pixels, generally independentof the degree of pupil dilation.

Referring to FIG. 10, a visible image A and infrared image B arepresented for comparison. Further, in image A, multiscale, quadraturewavelet iris code is illustrated in the upper left hand corner asdesignated by reference numeral 300. In one form, subsystem 70 output isprocessed to determine location of pupil P to process the image of irisI. A dedicated, highly integrated digital circuit can be provided toperform on-the-fly iris imaging and processing. In one form, codeprocessing is performed by a Field Programmable Gate Array (FPGA)arranged to perform the desired processes. Notably, this arrangement canbe used to process iris images provided by one or more differentwavelengths. In one particular form, multiple infrared (IR) images areprocessed in this manner. For further background information concerningiris processing, reference is made to J. Daugman, “How Iris RecognitionWorks” [www.CL.cam.ac.uk/users/jgd1000/]; J. Daugman, “Biometric ProductTesting” [www.cl.cam.ac.uk/users/jgd1000/NPLsummary.gif]; J. Daugman,“The Importance of Being Random: Statistical Principles of IrisRecognition” (Elsevier Science Ltd. 2002), all of which are herebyincorporated by reference.

Referring to FIG. 9, procedure 320 of a further embodiment of thepresent application is illustrated in flowchart form. Procedure 320 canbe implemented with system 220, performing various operations andconditionals in accordance with operating logic of correspondingsubsystems. Procedure 320 begins with operation 322 in which scanning ofa scene is performed. Such a scene is illustrated in FIG. 8 as indicatedby reference numeral 222. From the scanned face(s) of the scene,iris/pupil location is determined utilizing subsystem 70 in operation324. From operation 324, procedure 320 continues with operation 326 inwhich iris images are evaluated to provide a corresponding iris code orother iris identification information. In one form, a quadrature waveletform of iris code is determined in operation 326; however, in otherforms different techniques can additionally or alternatively beutilized.

Procedure 320 continues with operation 328 in which the generated irisinformation is compared to an identification database. Such database maybe local or remote relative to system 220. In one example, databaseinformation is at least partially provided through computer network 30.From operation 328, procedure 320 continues with conditional 330.Conditional 330 tests whether a match was identified in operation 328.If the test of conditional 330 is true (affirmative), the correspondingmatch condition is indicated by providing an alert in operation 322. Ifthe test of conditional 330 is false (negative), then procedure 320continues with conditional 334. From operation 332, procedure 320proceeds to conditional 334. Conditional 334 tests whether to continueexecution of procedure 320 by scanning an additional scene or rescanningas appropriate. If the test of conditional 334 is true (affirmative),procedure 320 loops back, returning to operation 332 to performoperation sequence 322-328 again. This sequence may be repeated via theloop back from conditional 334 as desired. If the test of conditional334 is false (negative), then procedure 320 halts.

As previously indicated, numerous variations, forms, and embodiments ofthe present application are envisioned. In another form, the irisevaluation/comparison of procedure 320 is performed in addition toprocedure 220 in which a 3-D facial feature comparison is made. In stillother embodiments, other recognition/identification techniques may becombined with procedures 120 and/or 320 as desired.

Monitoring humans for biometric analysis is applicable to a wide rangeof technologies for purposes of identification, verification, unknownthreat recognition, access control, security checkpoints, and the like.Nonetheless, in other embodiments, the transmission/receptionarrangement can differ. For example, in one alternative embodiment, oneor more elements 38 are used for both transmission and reception. Inanother alternative embodiment, a mixture of both approaches isutilized. Typically, the signals received from array 36 are downshiftedin frequency and converted into a processable format through theapplication of standard techniques. In one form, transceiver 42 is of abi-static heterodyne Frequency Modulated Continuous Wave (FM/CW) typelike that described in U.S. Pat. No. 5,859,609 (incorporated byreference herein). Commonly owned U.S. Pat. Nos. 6,703,964 B2; 6,507,309B2; 5,557,283; and 5,455,590, each of which are incorporated byreference herein, provide several nonlimiting examples of transceiverarrangements. In still other embodiments, a mixture of differenttransceiver/sensing element configurations with overlapping ornonoverlapping frequency ranges can be utilized that may include one ormore of the impulse type, monostatic homodyne type, bi-static heterodynetype, and/or such other type as would occur to those skilled in the art.

Another embodiment includes: directing multiple wavelengths ofelectromagnetic radiation to scan a face of a person; detecting at leastone of the wavelengths reflected by a first portion of an eye of theperson to establish a first signal and at least one other of thewavelengths reflected by a second portion of the eye through a pupilthereof to establish a second signal; evaluating these signals toprovide a value that varies with distance separating the first portionand the second portion; and determining location of the eye as afunction of the value. In one form, the second portion is behind thefirst portion of the eye—the second portion being a retina.

Still another embodiment of the present application includes:interrogating the face of a person with coherent electromagneticradiation including at least one wavelength reflected by a first portionof an eye and at least one other wavelength reflected by a secondportion of the eye, with the second portion being behind and interior tothe first portion. This embodiment further includes determining locationof the eye based on the interrogation, where such location correspondsto a difference in range relative to the first and second portions andcharacterizing at least part of the face relative to the location of theeye for comparison to identification information. In one form, thischaracterization includes evaluating three-dimensional facialinformation corresponding to at least a portion of the face.Alternatively or additionally, this embodiment may include locating adifferent eye of the person based on a range difference, determiningdistance separating the eyes, and/or performing the characterization asa function of this distance.

Yet another embodiment includes: detecting reflection of one or morewavelengths of electromagnetic radiation by a first boundary along aface of a person; detecting reflection of one or more other wavelengthsof electromagnetic radiation by a second boundary along the face;recognizing one or more portions of the face based on one of the firstand second boundaries at least partially covering another of the firstand second boundaries; and comparing at least part of the face toidentification information in accordance with this recognition. In oneform, the first boundary corresponds to makeup or a disguise placed onthe face, where the second boundary might be facial skin.

A further embodiment includes a facial scanning arrangement with a firstlaser to provide coherent electromagnetic radiation including a firstwavelength, a source to provide electromagnetic radiation including asecond wavelength, and one or more detectors to sense returnedelectromagnetic radiation of at least each of these wavelengths. Alsoincluded is a processing subsystem coupled to the facial scanningarrangement that is responsive to signals from the one or more detectorsto locate one or more portions of the face of a person scanned with thearrangement by detecting reflection of at least the first wavelength ofthe electromagnetic radiation by a first boundary along the face andreflection of at least the second wavelength of the electromagneticradiation by a second boundary along the face. One of these boundariesat least partially covers another of these boundaries, and theprocessing subsystem is operable to compare at least part of the face toidentification information in accordance with location of the one ormore portions of the face. In one form, this embodiment includes theprocessing subsystem evaluating three-dimensional facial informationrelative to the identification information.

Still a further embodiment of the present invention is a systemincluding: a facial scanning arrangement including a first laser toprovide coherent electromagnetic radiation including a first wavelength,a source to provide electromagnetic radiation including a secondwavelength in a range of preferably about 0.1 mm to about 100 mm and oneor more detectors to sense returned electromagnetic radiation of atleast the first and the second wavelengths. This system further includesa processing subsystem operatively coupled to the facial scanningarrangement that is responsive to signals from the detectors todetermine a difference in range between two locations along a face of aperson scanned therewith. One of these locations at least partiallycovers another of these locations and corresponds to reflection of thefirst wavelength while the other of the locations corresponds toreflection of the second wavelength as detected with the one or moredetectors. The processing subsystem is further operable to recognizethat the disguising material is on the face and is a function of thedifference in range. The processing subsystem is further operable toidentify the person based on evaluation of at least one iris of an eye,and/or determine location of one or more eyes of the person based on alaser ranging subsystem. In a more preferred embodiment, the range ofelectromagnetic radiation is about 1 mm to about 50 mm. In an even morepreferred embodiment, this range is about 1 mm to about 10 mm.

Yet a further embodiment of the present invention includes: means fordetecting reflection of one or more wavelengths of electromagneticradiation by a first boundary along a face of a person; means fordetecting reflection of one or more other wavelengths of theelectromagnetic radiation by a second boundary along the face; means forrecognizing one or more portions of the face based on one of the firstand second boundaries at least partially covering another of the firstand second boundaries; and means for comparing at least one of theseportions to identification information.

Another embodiment of the present invention includes: scanning a face ofa person with laser equipment; determining eye location from this scanbased on range information from the equipment that is indicative of afirst eye portion being separated from and in front of a second eyeportion; generating identification information for an iris of the eyelocated relative to the eye location; and comparing this identificationinformation to data from an identification database.

For yet another embodiment, a system includes: a facial scanningarrangement with laser equipment to interrogate a person withelectromagnetic radiation, which is operable to provide rangeinformation and image data. This system also includes a processingsubsystem responsive to the facial scanning arrangement to generate anumber of signals. These signals are representative of eye locationdetermined from the range information, identification informationdetermined from the image data for an iris of the eye located with theeye location, and a comparison of the identification information to datafrom an identification database. An output device may also be includedthat is responsive to one or more of the signals if the comparisonindicates a match of the person to an individual characterized in thedatabase.

Still another embodiment of the present invention includes: scanning aface of a person with laser equipment; determining eye location from thescan based on range information; generating three-dimensional facialfeature information relative to the eye location; and comparing thethree-dimensional facial feature information to data from anidentification database.

Still another embodiment includes: a facial scanning arrangement withlaser equipment and a processing subsystem responsive to sucharrangement. The processing subsystem generates a number of signals thatare representative of eye location determined from range informationprovided by the laser equipment, three-dimensional facial featureinformation determined relative to the eye location, and at least onecomparison of the three-dimensional facial feature information to datafrom an identification database.

A further embodiment includes: means for scanning a face of a personwith laser ranging equipment; means for determining an eye of the personbased on range information from the scanning means; at least one ofmeans for generating identification information from image data for aniris of the eye and means for generating three-dimensional facialfeature information relative to the eye location; and means forcomparing the identification information to data from an identificationdatabase.

Still a further embodiment is directed to a method that includes:directing multiple wavelengths of electromagnetic radiation to scan anobject including a retro-reflector, detecting at least one of thewavelengths reflected by a first portion of the object to establish afirst signal, detecting at least one other of the wavelengths reflectedby a second portion of the object to establish a second signal, anddetermining a relative location or distance as a function of the firstsignal and the second signal. In other embodiments of the presentapplication, apparatus, systems, devices, and the like can be providedthat implement this method.

As used herein, “millimeter wave” or “millimeter wavelength” refers toany electromagnetic radiation that has a wavelength in the range fromabout 0.1 millimeter to about 100 millimeters when propagating throughfree space. Also, as used herein, it should be appreciated that:variable, criterion, characteristic, comparison, quantity, amount,information, value, level, term, constant, flag, data, record,threshold, limit, input, output, pixel, image, matrix, command, look-uptable, profile, schedule, or memory location each generally correspondto one or more signals within processing equipment of the presentinvention. It is contemplated that various operations, stages,conditionals, procedures, thresholds, routines, and processes describedin connection with the present invention could be altered, rearranged,substituted, deleted, duplicated, combined, or added as would occur tothose skilled in the art without departing from the spirit thereof. Itshould be noted that implementation of the disclosed embodiments of thepresent invention is not limited to those depicted in the figures.

All publications and patent applications cited in this specification areherein incorporated by reference as if each individual publication orpatent application were specifically and individually indicated to beincorporated by reference. Further, any theory, mechanism of operation,proof, or finding stated herein is meant to further enhanceunderstanding of the present invention, and is not intended to limit thepresent invention in any way to such theory, mechanism of operation,proof, or finding. While the invention has been illustrated anddescribed in detail in the drawings and foregoing description, the sameis to be considered as illustrative and not restrictive in character, itbeing understood that only selected embodiments have been shown anddescribed and that all equivalents, changes, and modifications that comewithin the spirit of the inventions as defined herein or by thefollowing claims are desired to be protected.

1. A method, comprising: providing an electromagnetic radiation emittingdevice; providing at least one electromagnetic radiation receivingdevice; directing multiple wavelengths of electromagnetic radiation fromthe electromagnetic emitting device to scan a face of a person;detecting at least one of the wavelengths reflected by a first portionof an eye of the person with the at least one electromagnetic radiationreceiving device to establish a first signal; detecting at least oneother of the wavelengths reflected by a second portion of the eyethrough a pupil thereof with the at least one electromagnetic radiationreceiving device to establish a second signal, the second portion beingbehind and interior to the first portion; and determining a location ofthe eye relative to one or more facial features as a function of thefirst signal and the second signal, the first signal and the secondsignal being indicative of a distance separating the first portion andthe second portion, wherein the first signal is determined as a functionof a first phase shift representative of a range to the first portion,the second signal is determined as a function of a second phase shiftrepresentative of range to the second portion, and wherein the act ofdetermining the location of the eye includes finding a differencebetween the first range and the second range to provide a value, andcomparing the value to a threshold amount indicative of eye location. 2.The method of claim 1, wherein the second portion includes a retina ofthe eye.
 3. The method of claim 1, wherein the first signal and secondsignal indicate a difference in range between the first portion and thesecond portion that correspond to the location of the eye, and whichincludes locating another eye of the person based on a second rangedifference.
 4. The method of claim 1, wherein the one of the wavelengthsis greater than 1.00 micrometer and the one other of the wavelengthsincludes a wavelength less than 1.00 micrometer.
 5. The method of claim4, wherein the wavelength greater than 1.00 micrometer is at least 1.40micrometers and the wavelength less than 1.00 micrometer is no more than0.95 micrometer.
 6. The method of claim 1, wherein the first signal isdetermined as a function of a first amplitude of reflection of the oneof the wavelengths from the first portion, the second signal isdetermined as a function of a second amplitude of reflection of the oneother of the wavelengths from the second portion, and the act ofdetermining the location of the eye includes determining a ratio betweenthe first amplitude and the second amplitude.
 7. The method of claim 1,wherein the electromagnetic radiation includes one or more wavelengthsbetween about 0.1 millimeter and 100 millimeters to determine if adisguising material at least partially covers the face.
 8. A method,comprising: providing a scanning apparatus comprising an electromagneticradiation emitting device and at least one electromagnetic radiationreceiving device; interrogating a face of a person with coherentelectromagnetic radiation from the electromagnetic radiation emittingdevice, the coherent electromagnetic radiation including at least onewavelength emitted by the electromagnetic radiation emitting device andreflected by a first portion of an eye of the face and at least oneother wavelength emitted by the electromagnetic radiation emittingdevice and reflected by a second portion of the eye, the second portionbeing behind and interior to the first portion; measuring a phase changeof the radiation reflected by the first portion and a phase change ofthe radiation reflected by the second portion; determining a location ofthe eye based on a phase difference between the radiation reflected bythe first and second portions; and characterizing at least part of theface relative to the location of the eye for comparison toidentification information.
 9. The method of claim 8, wherein the partof the face includes an iris of the eye and further comprisingevaluating an image of the iris for the comparison to the identificationinformation.
 10. The method of claim 8, wherein the electromagneticradiation includes one or more wavelengths between about 0.1 millimeterand 100 millimeters to determine if a disguising material at leastpartially covers the face.
 11. The method of claim 8, wherein the secondportion includes a retina of the eye.
 12. The method of claim 11, whichincludes locating a different eye of the person based on a second rangedifference, determining distance separating the eye and the differenteye, and performing the characterizing as a function of the distance.13. The method of claim 8, wherein the at least one wavelength isgreater than or equal to 1.40 micrometers and the at least one otherwavelength includes a wavelength less than or equal to 0.95 micrometer.14. The method of claim 8, wherein the characterizing includesevaluating three-dimensional facial information.
 15. A method,comprising: providing at least one electromagnetic radiation emittingdevice and at least one electromagnetic radiation receiving device;scanning a face of a person to detect reflection of one or morewavelengths of electromagnetic radiation by a first boundary along aface of a person with the at least one electromagnetic radiationreceiving device; detecting reflection of one or more other wavelengthsof electromagnetic radiation by a second boundary along the face withthe at least one electromagnetic radiation receiving device, thedetected reflection from the second boundary passing through at least aportion of the first boundary that overlaps the second boundary;measuring a phase change of the radiation reflected by the first portionand a phase change of the radiation reflected by the second portion;determining spatial coordinates of the face by determining a phasedifference between the radiation reflected by the first and secondportions; recognizing one or more portions of the face based on thedetermination of the spatial coordinates of the face; and comparing atleast part of the face to identification information in accordance withthe recognizing.
 16. The method of claim 15, wherein the first boundarycorresponds to an outer surface of an eye of the face, and the one ormore portions of the face include the eye.
 17. The method of claim 15,wherein the first boundary corresponds to make-up or a disguise on theface.
 18. The method of claim 15, wherein the one or more portions ofthe face include an eye of the face and further comprising imaging aniris of the eye to compare to the identification information.
 19. Themethod of claim 15, which includes interrogating the face withelectromagnetic radiation including one or more wavelengths betweenabout 0.1 millimeter and 100 millimeters to determine if a material atleast partially covers the face.
 20. The method of claim 15, wherein theone or more wavelengths include a wavelength greater than or equal to1.40 micrometers and the one or more other wavelengths include awavelength less than or equal to 0.95 micrometer.
 21. The method ofclaim 15, which includes locating each of two eyes of the face asfunction of at least one of an amplitude difference and a phasedifference.
 22. The method of claim 1, further comprising: performing ananalysis of an iris of the eye located by the act of determining thelocation of the eye; wherein the performing of the analysis of the iriscomprises detecting at least one of the wavelengths reflected by theiris.
 23. The method of claim 1, wherein one or more of the multiplewavelengths of electromagnetic radiation are amplitude modulated. 24.The method of claim 1, wherein the first phase shift is determinedsimultaneously with a determination of a first amplitude of thewavelength reflected by the first portion of the eye, and the secondphase shift is determined simultaneously with a determination of asecond amplitude of the wavelength reflected by the second portion ofthe eye.
 25. The method of claim 8, wherein the electromagneticradiation emitting device comprises a multispectral source having atleast two lasers, the at least two lasers including a first laser and asecond laser that are substantially optically aligned and emit radiationthat is synchronously amplitude modulated, wherein the first laser emitsradiation with the at least one wavelength and the second laser emitsradiation with the at least one other wavelength.
 26. The method ofclaim 8, further comprising: measuring an intensity of the radiationreflected by the first portion and an intensity of the radiationreflected by the second portion, wherein the determining of the locationof the eye is also based on determining a change in the relativeintensities of the radiation reflected by the first and second portions.27. The method of claim 15, wherein the electromagnetic radiationemitting device comprises a multispectral source having at least twolasers, the at least two lasers including a first laser that emits aradiation of a first wavelength and a second laser that emits radiationof a second wavelength, the first and second lasers being substantiallyoptically aligned and emitting radiation that is synchronously amplitudemodulated.
 28. The method of claim 15, further comprising: measuring anintensity of the radiation reflected by the first portion and anintensity of the radiation reflected by the second portion, wherein thedetermining of the spatial coordinates of the face is also based ondetermining a change in the relative intensities of the radiationreflected by the first and second portions.